An eastbound BNSF freight train passes over itself at the Tehachapi Loop between Bakersfield and Mojave, California. The Tehachapi Loop is a .73 miles (1.17 km) long 'spiral', or helix, on the railroad main line. A train more than 4,000 feet (1.2 km) long (about 85 boxcars) will pass over itself going around the loop. In 1998 it was named a National Historic Civil Engineering Landmark.